Paraldehyde is a sedative-hypnotic drug which has been used in medicine for close to 100 years. Chemically it is a polymer of acetaldehyde into which it is readily depolymerized by acid and less readily by light. It has been frequently hypothesized that likewise paraldehyde is depolymerized in vivo with further metabolism to acetate and carbon dioxide. There is however no concrete evidence to support this hypothesis and no metabolites of paraldehyde have been identified. Moreover, it is not known how fast paraldehyde is cleared from human blood, be it in infants or adults. Yet it is generally agreed that for rational therapy it is essential to know the rate of elimination of the drug employed, its metabolic fate and metabolic effects. The overall goal of this proposed investigation is to provide this information. The proposed research seeks to determine the pathway whereby 14C paraldehyde is metabolized in vivo to 14CO2, to determine whether there is any intermediary production of acetaldehyde, and what meabolites other than CO2 are produced. Concurrently it seeks to determine how rapidly and by what process paraldehyde is cleared from the bloodstream of infants receiving it for the control of seizures or status.